<!DOCTYPE html>
<html lang="zc-CN">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <form>
        <input type="file" name="avatar" accept="image/*" placeholder="请选择头像" />
        <button>上传文件</button>
    </form>
    <img src="" alt="" class="avatar" style="width: 500px" />
</body>
<script src="./axios.js"></script>
<script>
    const form = document.querySelector('form');
    const avatar = document.querySelector('.avatar');
    form.addEventListener('submit', function (e) {
        e.preventDefault()
        const fd = new FormData(form)
        axios.post(
            'http://ajax-api.itheima.net/api/file',
            fd
        ).then(({ data: res }) => {
            // console.log(res);
            const url = res.data.url
            avatar.src = url
        })
    })
</script>

</html>